Vibration damping system

ABSTRACT

Clothes driers include a cabinet, a rotatable drum mounted inside the cabinet, and one or more vibration dumpers mounted to the rotatable drum. The vibration dampers may be mounted inside the drum, between baffles and the drum. The vibration dampers may be attached to the rotatable drum, such that a largest dimension of the vibration dampers extends in a direction of length of the rotatable drum. The vibration dumpers may be configured to shift acoustic energy generated at the front of the drum toward the rear of the drum.

RELATED APPLICATIONS

This application claims the benefit of U.S. provisional application No. 62/013,615 filed on Jun. 18, 2014, titled “Vibration Damping System” which is incorporated herein by reference in its entirety.

BACKGROUND

1. Field of the Invention

The present relates to a method and apparatus for vibration (e.g., sound) damping.

2. Description of Related Art

The damping of vibration of mechanical systems is of increasing importance to industry in that vibration can have a number of undesirable effects. For instance, consumers are becoming increasingly sensitive to the undesirability of sound created by vibrating systems. Automobile manufacturers have recognized the importance in the purchasing decision of many buyers of a solid thump sound when an automobile door is closed. Likewise, the quality of an appliance is sometimes gauged in part by the perception of the solidity of its construction.

It has become important for the manufacturers of appliances such as clothes washers and dryers, refrigerators, microwave ovens, ovens, stoves, dishwashers, etc. to provide vibration damping on the large, flat sheet material sides of the appliances so that a consumer in making his or her purchasing decision can appreciate the quality of the product by the low frequency sound generated when the side of the appliances is hit. Also, provision of such systems can be important to reduce the noise levels produced by the appliance when such sides vibrate. This is especially true today because of the increase in homes that locate such appliances on the main living floor thereof.

Sound damping systems generally operate by converting vibration energy into thermal energy. For instance, the vibration energy may be converted into thermal energy by interfacial friction, which makes it exhibit a vibration damping property. Alternatively or in addition, shear deformation may be produced within an elastic material having a small elastic modulus when it is located between a source of vibration energy and another surface or constraining layer.

Pre Finish Metals Inc. provides a product called Polycore® which consists of metal outer skins surrounding a thin, viscoelastic core material. This inner core converts the mechanical energy of vibration into heat and then dissipates the heat. This combination is purported to reduce vibration generated noise at the source. Similarly, 3M provides products under the name “Scotchdamp™ vibration control systems” in which any one of a variety of adhesive layers join a constraining layer to a source of vibrating sound. The shear modulus and sound loss factors of these products depend on frequency and temperature, as well as on other factors.

In addition to adhesives, magnetic materials may join a constraining layer to a source of vibratory sound. For instance, in U.S. Pat. No. 5,300,355, the disclosed vibration damping material includes a magnetic composite type damping material constructed by bonding an adhesive elastic sheet containing magnetic powder to a constraining plate such as a metal plate. In this system, it is reported that since not only is the damping material attracted by a magnetic force against a vibration source, it is also provided with a superficial adhesiveness to develop vibration damping properties over a wide range of temperatures.

Domestic clothes drying machines typically comprise a rotating steel dryer drum in which clothes are tumbled as warm air is circulated through the dryer drum drying the clothes. As the articles of clothing tumble within the dryer drum, the articles fall into contact with the drum wall. Heavier articles, metal buttons and loose coins have a tendency to impact the dryer drum and create noise.

U.S. Pat. No. 5,901,465 discloses a clothes dryer with a reduced noise drum. Steel bands or straps are fastened about the outside periphery of the cylindrical wall of the dryer drum to absorb noise created by articles tumbling within the dryer drum during operation. An adhesive material is laminated to the strap or band which sticks the band to the outside wall of the dryer drum by applying pressure. Baffle mounting screws passing through the dryer drum also secure ends and intermediate parts of the band to the dryer drum.

SUMMARY

The present application discloses exemplary embodiments of clothes driers. The clothes driers include a cabinet, a rotatable drum mounted inside the cabinet, and one or more vibration dampers mounted to the rotatable drum. The vibration dumpers may have a variety of different configurations. The vibration dampers may be mounted inside the drum, between baffles and the drum. The vibration dampers may be attached to the rotatable drum, such that a largest dimension of the vibration dampers extends in a direction of length of the rotatable drum. The vibration dumpers may be configured to shift acoustic energy generated at the front of the drum toward the rear of the drum.

Various objects and advantages will become apparent to those skilled in the art from the following detailed description of the invention, when read in light of the accompanying drawings. It is to be expressly understood, however, that the drawings are for illustrative purposes and are not to be construed as defining the limits of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a clothes dryer;

FIG. 2A is a perspective view of a clothes dryer drum with a baffle and dampener separated from the drum;

FIG. 2B is a sectional view showing attachment of the baffle and dampener shown in FIG. 2A to the drum;

FIG. 3A illustrates an exemplary embodiment of a clothes dryer drum having an exemplary embodiment of a sound dampening system;

FIG. 3B is a sectional view taken along the plane indicated by lines 3B-3B in FIG. 3A;

FIG. 3C is a sectional view taken along the plane indicated by lines 3C-3C in FIG. 3B;

FIG. 4A illustrates an exemplary embodiment of a clothes dryer drum having an exemplary embodiment of a sound dampening system;

FIG. 4B is a sectional view taken along the plane indicated by lines 4B-4B in FIG. 4A;

FIG. 4C is a sectional view taken along the plane indicated by lines 4C-4C in FIG. 4B;

FIG. 5A illustrates an exemplary embodiment of a clothes dryer drum having an exemplary embodiment of a sound dampening system;

FIG. 5B is a sectional view taken along the plane indicated by lines 5B-5B in FIG. 5A;

FIG. 5C is a sectional view showing attachment of the sound dampening system shown in FIGS. 5A and 5B;

FIG. 6A illustrates an exemplary embodiment of a clothes dryer drum having an exemplary embodiment of a sound dampening system;

FIG. 6B is a sectional view taken along the plane indicated by lines 6B-6B in FIG. 6A;

FIG. 7A illustrates an exemplary embodiment of a clothes dryer drum having an exemplary embodiment of a sound dampening system;

FIG. 7B is a sectional view taken along the plane indicated by lines 7B-7B in FIG. 7A;

FIG. 8A illustrates an exemplary embodiment of a clothes dryer drum having an exemplary embodiment of a sound dampening system;

FIG. 8B is a sectional view taken along the plane indicated by lines 8B-8B in FIG. 8A;

FIG. 9A illustrates an exemplary embodiment of a clothes dryer drum having an exemplary embodiment of a sound dampening system;

FIG. 9B is a sectional view taken along the plane indicated by lines 8B-8B in FIG. 8A;

FIG. 10A illustrates an exemplary embodiment of a clothes dryer drum having an exemplary embodiment of a sound dampening system;

FIG. 10B is a sectional view taken along the plane indicated by lines 10B-10B in FIG. 10A;

FIG. 11A illustrates an exemplary embodiment of a clothes dryer drum having an exemplary embodiment of a sound dampening system;

FIG. 11B is a sectional view taken along the plane indicated by lines 11B-11B in FIG. 11A;

FIG. 12A illustrates an exemplary embodiment of a clothes dryer drum having an exemplary embodiment of a sound dampening system;

FIG. 12B is a sectional view taken along the plane indicated by lines 12B-12B in FIG. 12A;

FIG. 13A illustrates an exemplary embodiment of a clothes dryer drum having an exemplary embodiment of a sound dampening system;

FIG. 13B is a sectional view taken along the plane indicated by lines 13B-13B in FIG. 13A;

FIG. 13C is a sectional view taken along the plane indicated by lines 13C-13C in FIG. 13B;

FIG. 14A is a cross-sectional view of an exemplary embodiment of a vibration damper;

FIG. 14B is a cross-sectional view of an exemplary embodiment of a vibration damper;

FIG. 15A is a cross-sectional view of an exemplary embodiment of a vibration damper;

FIG. 15B is a cross-sectional view of an exemplary embodiment of a vibration damper;

FIG. 16 is a perspective view of an exemplary embodiment of a stiffened vibration damper;

FIG. 17 is a side view of an exemplary embodiment of a stiffened vibration damper;

FIG. 18 illustrates an exemplary embodiment of a clothes dryer drum having an exemplary embodiment of a sound dampening system;

FIG. 19 illustrates an exemplary embodiment of a clothes dryer drum having an exemplary embodiment of a sound dampening system; and

FIG. 20 illustrates an exemplary embodiment of a clothes dryer drum having an exemplary embodiment of a sound dampening system.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will now be described with occasional reference to the specific embodiments of the invention. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for describing particular embodiments only and is not intended to be limiting of the invention. As used in the description of the invention and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Unless otherwise indicated, all numbers expressing quantities of dimensions such as length, width, height, and so forth as used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless otherwise indicated, the numerical properties set forth in the specification and claims are approximations that may vary depending on the desired properties sought to be obtained in embodiments of the present invention. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical values, however, inherently contain certain errors necessarily resulting from error found in their respective measurements.

Referring to FIG. 1 a clothes dryer 10 is illustrated to show some of the basic details of the construction. The dryer 10 may be heated by gas or electricity. The dryer 10 includes a cabinet or housing 12 that includes a control panel 14. A rotating drum 16, motor 18 and blower 20 are housed within the cabinet 12. The cabinet 12 has front wall 25 with a door 21 to give the user access to the drum 16 through an access opening 23. The drum 16 is mounted in the cabinet 12 for rotation about its central axis. The motor 18 is arranged to drive the drum by means of belt 22. Heated air is forced into the drum by the blower 20 through a vent 29 to extract moisture from clothes that tumble in the drum 16. The illustrated vent 29 and drum 16 configuration is one of many possible configurations and is not intended to limit the present application in any way.

Referring to FIG. 2, in an exemplary embodiment, the drum 16 is provided with a set of baffles 24. The baffles 24 can be provided in a wide variety of different configurations. In the illustrated embodiments, the baffles 24 extend substantially the entire length L_(DRUM) of the drum. In other exemplary embodiments, the baffles 24 may extend about ½ the length L_(DRUM) of the drum 16. For example, separate, shorter baffles may be provided on each side of the groove 21. In one exemplary embodiment, four baffles having about ½ the length L_(DRUM) of the drum can be provided, with two diametrically offset in the front and two diametrically offset in the back. These front and rear “½ baffles” can be offset from one another by 90 degrees. The dampers 100 disclosed herein are equally applicable to the “½ baffles” as they are to the illustrated full length baffles.

The baffles 24 can take a wide variety of different forms. In one exemplary embodiment, the baffles 24 are each a substantially hollow and are molded from plastic. A wide variety of different plastics can be used. Any plastic that can withstand the temperatures inside the drum 16 during operation of the dryer 10 and can withstand impact by clothes and other articles inside the drum 16 can be used to construct the baffles 24. Examples of plastic materials for the baffle 24 include, but are not limited to, vinyl, polypropylene, and NORYL, trademark of General Electric Company. The baffle 24 may have a variety of different shapes and sizes. In an exemplary embodiment, three or more equally circumferentially spaced baffles are provided. In another exemplary embodiment, baffles are omitted or are substantially omitted. In one exemplary embodiment, the baffle is slightly curved so as to encourage the clothes to tumble toward the center of the drum 16 during a drying operation. The baffle 24 may be mounted to the drum 16 in a wide variety of different ways. In one exemplary embodiment, the baffle 24 is mounted by bolts or screws 200 to an inside surface 26 of a cylindrical drum sidewall 28.

The drum 16 can be driven in a wide variety of different ways. In one exemplary embodiment, the drive belt 22 is disposed around the drum 16. The drive belt 22 is driven by the motor 18 to rotate the drum 16 inside the cabinet 12. The drive belt 22 may be disposed around the drum in a wide variety of different ways. In one exemplary embodiment, an optional groove 21 receives the belt. The optional belt receiving groove can take a wide variety of different forms. For example, a circumferential indentation may be formed in the cylindrical drum sidewall 28 to define the groove 21 (see FIG. 4A). In another exemplary embodiment, struts or webs may be provided on an outside surface 32 of the cylindrical sidewall 28 of the drum to define a belt receiving groove 21.

In an exemplary embodiment, an appliance, such as the dryer 10 illustrated by FIG. 1 is provided with one or more vibration dampers 100. The vibration damper can take a wide variety of different forms and can be applied to the appliance in a wide variety of different ways. For example, the vibration damper 100 may be a frictional type damper, a free layer type damper, or a constrained layer type damper. A frictional type damper may be an underlayment made of foam or fibers.

FIGS. 14A and 15A illustrate exemplary embodiments of free layer type damper. The free layer type damper includes a layer 1413 of viscoelastic material on the surface of the component with vibration that is being damped (the dryer drum 16 in FIGS. 14A and 15A). The layer 1413 of damping material is adhered to the surface of a structure, such as the dryer drum 16. Energy is dissipated as a result of extension and compression of the damping material layer 1413 when the base structure (dryer drum 16 in the example) is flexing during vibration. The damping is dependent on the composition of a damping material of the free layer damper and increases with damping layer thickness. The viscoelastic material of the may be asphaltic, such as pressure sensitive asphaltic adhesive, magnetic, and/or Butyl, such as pressure sensitive adhesive and non-adhesive butyl. The viscoelastic material may be sprayed on the structure, such as the drum 16 or the viscoelastic material may be pre-formed and applied to the structure.

FIGS. 14B and 15B illustrate exemplary embodiments of constrained layer type damper. The constrained layer type damper includes a layer 1413 of viscoelastic material on the surface of the component with vibration that is being damped (the dryer drum 16 in FIGS. 14B and 15B) and a constraining layer 1412 on the viscoelastic material. The layer 1413 of damping material is affixed to the surface of a structure, such as the dryer drum 16. A “sandwich” is formed by laminating a damping layer in between the structure, such as the dryer drum, and the constraining layer. When the system flexes during vibration, shear strains develop in the damping layer and energy is lost through shear deformation of the layer 1413 of viscoelastic material. Varying layer thickness ratios permits optimizing system loss factors for various temperatures without changing the layer 1413 of viscoelastic material composition. Examples of constrained layer dampers include, but are not limited to, conformable constrained layer (CCL) dampers, patch constrained layer dampers, and aluminum backed butyl constrained layer dampers.

Referring to FIGS. 2 and 3A-3C, in one exemplary embodiment, a vibration damper 100 is provided between each baffle 24 and the inside surface 26 of the drum 16. Referring to FIGS. 3B and 3C, in an exemplary embodiment a perimeter 300 of the vibration damper 100 is sized and shaped to match a size and shape of a perimeter 302 of a base 304 of the baffle. As such, a smooth transition is provided from the inside surface 26 to the perimeter 300 of the vibration damper 100 to the perimeter 302 of the base 304 of the baffle 24. This smooth transition prevents any snagging of clothes on the vibration damper 100 or the base 304 of the baffle 24. In one exemplary embodiment, a bottom surface 306 of the damper 100 is contoured to match the contour of the inside surface 26 of the drum 16. For example the bottom surface 306 of the damper 100 may be curved across its width W (see FIG. 3B) to match the curvature of the inside surface 26 of the drum 16.

Any of the vibration dampers 100 and the baffle 24 disclosed by the present application can be secured to the drum 24 in a wide variety of different ways. In the exemplary embodiment illustrated by FIGS. 2A and 2B, the vibration damper 100 is secured to the drum 16 with the same fasteners 200 that secure the baffle 24 to the drum 24. For example, during assembly, each vibration damper 100 is placed between a baffle 24 and the inside surface 26 of the drum 16. Referring to FIG. 2B, the vibration damper 100 is aligned with the baffle 24 and apertures 42 in the vibration damper 100 are aligned over apertures 43 through the drum 16. A securing screw 200 extends through the aperture 43 in the drum 16, through the aperture 42 in the vibration damper 100, and threads into a mounting portion 52 of the baffle 24 to secure both the baffle 24 and the vibration damper 100 to the drum 16.

FIGS. 4A-4C illustrate an exemplary embodiment where the drum 16 includes the optional groove 21 for the belt 26. Referring to FIGS. 4B and 4C, in an exemplary embodiment a perimeter 300 of the vibration damper 100 is sized and shaped to match a size and shape of a perimeter 302 of a base 304 of the baffle. In this embodiment, the length L_(D) of the vibration damper 100 matches or substantially matches the length L_(B) of the baffle 24, even though the drum 16 includes the groove. A smooth transition is provided from the inside surface 26 to the perimeter 300 of the vibration damper 100 to the perimeter 302 of the base 304 of the baffle 24. This smooth transition prevents any snagging of clothes on the vibration damper 100 or the base 304 of the baffle 24. In one exemplary embodiment, a bottom surface 306 of the damper 100 is contoured to match the contour of the inside surface 26 of the drum 16. For example the bottom surface 306 includes a groove 400 that matches the contour of an annular projection 402 on the inside surface 26 of the drum that is created by forming the groove 21 in the outside surface 32 of the drum. The damper 100 may also optionally be curved across its width W to match the curvature of the inside surface 26 of the drum 16.

FIGS. 5A-5C illustrate an exemplary embodiment where dampers 100 that extend along a length L_(DRUM) of the drum 16 are secured to the outside surface 32 of the drum 16. In one exemplary embodiment, a vibration damper 100 is provided on the outside surface 32 of the drum 16, behind each baffle. In the example illustrated by FIGS. 5A and 5B, the dampers are positioned on the outside surface 32 of the drum 16 between the access opening 23 and the belt groove 21.

Referring to FIGS. 5B and 5C, in an exemplary embodiment a perimeter 300 of the vibration damper 100 on the outside surface 32 need not be sized and shaped to match a size and shape of a perimeter 302 of a base 304 of the baffle. The shape and size of the vibration damper 100 can be adjusted or tuned to provide an appropriate amount of vibration in selected locations of the drum 16. In the example illustrated by FIGS. 5B and 5C, the width of the vibration damper 100 is greater than the width of the base 304 of the baffle 24. In other exemplary embodiments, the width of the vibration damper 100 can match the width of the width of the base 304 of the baffle or the width of the vibration damper 100 can be less than the width of the base 304 of the baffle. Further, the size of the vibration damper 100 can vary along the length of the drum. For example, the vibration damper 100 may have a wider portion toward the access opening 23, where sound is most likely to emanate, and a narrower portion that is further away from the access opening 23. This provides more damping where it is needed most (near the front of the dryer 10) and less where it may not needed as much (toward the rear of the dryer). In some exemplary embodiments, the length of the damper 100 (in the direction of the length L_(DRUM)) is greater than the width W of the damper 100. In other exemplary embodiments, the length of the damper 100 (in the direction of the length L_(DRUM)) is less than the width W of the damper 100. The dampers 100 can also have different shapes and sizes to further tune the vibration dampening.

In one exemplary embodiment, a bottom surface 306 of the damper 100 is contoured to match the contour of the outside surface 32 of the drum 16. For example the bottom surface 306 of the damper 100 may be curved across its width W to match the curvature of the outside surface 32 of the drum 16.

In the exemplary embodiment illustrated by FIG. 5C, the vibration damper 100 is secured to the drum 16 with the same fasteners 200 that secure the baffle 24 to the drum 16. Any of the vibration dampers 100 and baffles disclosed by this application can be secured to the drum 24 in this manner. For example, during assembly, each vibration damper 100 is placed against the outside surface 32 of the drum 16 and the baffle 24 is placed against the inside surface 26 of the drum. The apertures 42 in the vibration damper 100 are aligned over apertures 43 through the drum 16. A securing screw 46 extends through the aperture 42 in the vibration damper 100, through the aperture 43 in the drum 16, and threads into a mounting portion 52 of the baffle 24 to secure both the baffle 24 and the vibration damper 100 to the drum 16.

FIGS. 6A and 6B illustrate an exemplary embodiment that is similar to the embodiment illustrated by FIGS. 5A-5C, except the dampers 100 are positioned on the outside surface 32 of the drum 16 between the belt groove 21 and a rear end 600 of the drum 16.

FIGS. 7A and 7B illustrate an exemplary embodiment that is similar to the embodiment illustrated by FIGS. 5A-5C, except the dampers 100 are positioned both between the access opening 23 and the belt groove 21 and between the belt groove 21 and the rear end 600 of the drum 16. The dampers can be positioned in a wide variety of different configurations and can have a variety of different shapes and sizes. In the example illustrated by FIGS. 7A and 7B, the dampers 100 between the belt groove 21 and the rear end 600 of the drum 16 can have a different size than the dampers 100 between the access opening 23 and the belt groove 21. For example, the dampers 100 between the belt groove 21 and the rear end 600 of the drum 16 can be smaller, larger, and/or have a different shape than the dampers 100 between the access opening 23 and the belt groove 21.

FIGS. 8A and 8B illustrate an exemplary embodiment similar to the embodiment illustrated by FIGS. 5A-5C, except two dampers 100 are positioned behind two baffles 24 between the access opening 23 and the belt groove 21 and two dampers 100 are positioned behind two baffles 24 between the belt groove 21 and the rear end 600 of the drum 16. The dampers can be positioned in a wide variety of different configurations and can have a variety of different shapes and sizes. In the example illustrated by FIGS. 8A and 8B, the dampers 100 between the access opening 23 and the belt groove 21 are diametrically opposed. The dampers 100 between the belt groove 21 and the rear end 600 of the drum 16 are also diametrically opposed and are offset by 180 degrees from the dampers 100 between the access opening 23 and the belt groove 21. The dampers 100 between the belt groove 21 and the rear end 600 of the drum 16 can have a different size than the dampers 100 between the access opening 23 and the belt groove 21. For example, the dampers 100 between the belt groove 21 and the rear end 600 of the drum 16 can be smaller, larger, and/or have a different shape than the dampers 100 between the access opening 23 and the belt groove 21.

FIGS. 9A and 9B illustrate an exemplary embodiment where dampers 100 that extend along a length L_(DRUM) of the drum 16 are secured to the outside surface 32 of the drum 16. In one exemplary embodiment, the vibration dampers 100 is provided on the outside surface 32 of the drum 16, offset from the baffles. In the example illustrated by FIGS. 9A and 9B, the dampers 100 are positioned on the outside surface 32 of the drum 16 between the access opening 23 and the belt groove 21.

In an exemplary embodiment a perimeter 300 of the vibration damper 100 on the outside surface 32 may have a wide variety of different configurations. The shape and size of the vibration damper 100 can be adjusted or tuned to provide an appropriate amount of vibration in selected locations of the drum 16. In the example illustrated by FIG. 9B, the width of the vibration damper 100 is greater than the width of the base 304 of the baffle 24. In other exemplary embodiments, the width of the vibration damper 100 can match the width of the width of the base 304 of the baffle or the width of the vibration damper 100 or can be less than the width of the base 304 of the baffle. Further, the size of the vibration damper 100 can vary along the length of the drum. For example, the vibration damper 100 may have a wider portion toward the access opening 23, where sound is most likely to emanate, and a narrower portion that is further away from the access opening 23. This provides more damping where it is needed most (near the front of the dryer 10) and less where it may not needed as much (toward the rear of the dryer). The dampers 100 can also have different shapes and sizes to further tune the vibration dampening.

In the exemplary embodiment illustrated by FIG. 9B, a bottom surface 306 of the damper 100 is contoured to match the contour of the outside surface 32 of the drum 16. For example the bottom surface 306 of the damper 100 may be curved across its width W to match the curvature of the outside surface 32 of the drum 16. In other exemplary embodiments, the bottom surface 306 is not contoured. In the exemplary embodiment illustrated by FIGS. 9A and 9B, the vibration dampers 100 may be secured to the drum 16 with fasteners, adhesive, welding, and the like.

FIGS. 10A and 10B illustrate an exemplary embodiment that is similar to the embodiment illustrated by FIGS. 9A and 9B, except the dampers 100 are positioned on the outside surface 32 of the drum 16 between the belt groove 21 and a rear end 600 of the drum 16.

FIGS. 11A and 11B illustrate an exemplary embodiment that is similar to the embodiment illustrated by FIGS. 9A and 9B, except the dampers 100 are positioned both between the access opening 23 and the belt groove 21 and between the belt groove 21 and the rear end 600 of the drum 16. The dampers can be positioned in a wide variety of different configurations and can have a variety of different shapes and sizes. In the example illustrated by FIGS. 11A and 11B, the dampers 100 between the belt groove 21 and the rear end 600 of the drum 16 can have a different size than the dampers 100 between the access opening 23 and the belt groove 21. For example, the dampers 100 between the belt groove 21 and the rear end 600 of the drum 16 can be smaller, larger, and/or have a different shape than the dampers 100 between the access opening 23 and the belt groove 21.

FIGS. 12A and 12B illustrate an exemplary embodiment similar to the embodiment illustrated by FIGS. 9A and 9B, except two dampers 100 are positioned between the access opening 23 and the belt groove 21 and two dampers 100 are positioned between the belt groove 21 and the rear end 600 of the drum 16. The dampers can be positioned in a wide variety of different configurations and can have a variety of different shapes and sizes. In the example illustrated by FIGS. 12A and 12B, the dampers 100 between the access opening 23 and the belt groove 21 are diametrically opposed. The dampers 100 between the belt groove 21 and the rear end 600 of the drum 16 are also diametrically opposed and are offset by 180 degrees from the dampers 100 between the access opening 23 and the belt groove 21. The dampers 100 between the belt groove 21 and the rear end 600 of the drum 16 can have a different size than the dampers 100 between the access opening 23 and the belt groove 21. For example, the dampers 100 between the belt groove 21 and the rear end 600 of the drum 16 can be smaller, larger, and/or have a different shape than the dampers 100 between the access opening 23 and the belt groove 21.

The embodiments illustrated by FIGS. 3A-12B can be combined in a variety of different ways. For example, dampers 100 may be placed both inside and outside the drum 16, and/or behind and offset from the from the baffles 24. Any of the configurations illustrated by FIGS. 3A-12B can be combined with any of the other configurations to form additional damper configurations.

FIGS. 13A-13C illustrate and exemplary embodiment where the drum 16 is contoured. The drum 16 may be contoured in a in a wide variety of different ways. In the illustrated exemplary embodiment, the drum 16 is dimpled. The dimpled drum 1300 includes a pattern of dimples 1302 or indentations. The dimpled drum may be made from a wide variety of different materials. For example, the dimpled drum may be steel, such as stainless steel. The dimples 1302 and dimple patterns can take a wide variety of different forms. The dimples 1302 and the pattern of dimples can be uniform and/or non-uniform. In one exemplary embodiment, a stainless steel drum has a dimple pattern with deeper dimples in the middle of the drum 16 than on the front and rear portions of the drum.

Referring to FIG. 13C, in an exemplary embodiment the damper 100 is contoured to match the contour of the drum 16. For example, the illustrated damper 100 includes projections 1310 that match the contour of the pattern of dimples 1302. Dampers 100 that match the contour of the drum can be applied to the drum 16 in any of the configurations contemplated by FIGS. 3A-12B. The dampers 100 may be made to match the contour of the drum 16 with dimples 1302 in a wide variety of different ways. In one exemplary embodiment, an adhering layer 1413 may be spray applied to the drum to fill in the dimples 1302 and thereby match the contour of the dimpled drum 16. In another exemplary embodiment, the layer 1413 is made from a deformable material and the constraining layer 1412 is drawn down by the fasteners to press the layer 1413 into the dimples.

The dampers 100 can take a wide variety of different forms. One damper that can be used is a Polycore® from Pre Finish Metals Inc. Polycore® consists of metal outer skins surrounding a thin, viscoelastic core material. This inner core converts the mechanical energy of vibration into heat and then dissipates the heat. Another damper that can be used is Scotchdamp™ vibration control systems from 3M. In the Scotchdamp™ vibration control systems any one of a variety of adhesive layers joins a constraining layer to a source of vibrating sound. In addition to adhesives, magnetic materials may join a constraining layer to a source of vibratory sound. For instance, in U.S. Pat. No. 5,300,355, the disclosed vibration damping material includes a magnetic composite type damping material constructed by bonding an adhesive elastic sheet containing magnetic powder to a constraining plate such as a metal plate. U.S. Pat. No. 5,300,355 is incorporated herein by reference in its entirety.

U.S. Pat. No. 5,855,353 discloses examples of dampers 100 that can be used in the embodiments of the present application. U.S. Pat. No. 5,855,353 is incorporated herein by reference in its entirety. Referring to FIGS. 14B and 15B, in an exemplary embodiment the damper 100 includes a constraining layer 1412 and an adhering layer 1413. Referring to FIGS. 14A and 15A, in some exemplary embodiments, the constraining layer 1412 is omitted. In the illustrated embodiment, the constraining layer 1412 is an elongated metal bar or rectilinear plate, but can be shaped as a circular, ovoid, square, irregular, etc. any shape or contoured as desired. The constraining layer 1412 can include an appropriate configuration to assist in stiffening the drum 16. Such a stiffening configuration of the constraining layer 1412 can comprise bent edges 1416 running the length or width of a flat constraining layer 1412 (See FIG. 17) or a bend 1414 running the length of the constraining layer 1412 (See FIG. 16) to provide greater rigidity due to the angled surfaces of the cross-section of the constraining layer 1412. The bend 1414 can be chevron shaped as shown, or other shapes such as arcuate, rectilinear, etc., shaped may be used if desired.

Any suitable material can be used for the constraining layer 1412 provided the material has a large elastic modulus at least in one direction compared to the surface of the drum 16 to which it is applied. Stated in other terms, the constraining layer 1412 should have relatively higher flexural rigidity. In one exemplary embodiment, the constraining layer 1412 has a flexural rigidity that is at least eighty percent of the flexural rigidity of the drum sidewall. In one exemplary embodiment, the constraining layer 1412 has a flexural rigidity that is at as high as the flexural rigidity of the drum sidewall. In one exemplary embodiment, the constraining layer 1412 has a flexural rigidity that is higher than the flexural rigidity of the drum sidewall. In an exemplary embodiment, the constraining layer 1412 resists flexure of the drum 16 to which it is applied, thereby causing shear forces to develop in the adhering layer 1413 to thus convert vibration into heat energy. For instance, the constraining layer 1412 may have a large elastic modulus such as a plate made of sheet metal, iron, aluminum, stainless steel, copper, etc., a plastic plate made of phenol resin, polyamide, polycarbonate, polyester, etc., a fiber reinforced plastic plate fabricated by reinforcing the plastic plate using fiber such as glass fiber, carbon fiber, etc., or an inorganic rigid plate such as slate plate, hydrated calcium silicate plate, a plaster board, a fiber mixed cement plate, a ceramic plate, etc., or an organic rigid plate including asphalt, fiber impregnated with asphalt, wood, etc.

As shown in FIGS. 14B and 15B, the adhering layer 1413 is interposed between the constraining layer 1412 and the source of vibration such as the drum 16, such that it acts both to adhere the constraining layer 1412 to the drum 16 and damp the vibration of the drum 16. In the example illustrated by FIG. 14B, the adhering layer 1413 is composed of a viscosity enhancing material 1421 and an adhesive 1422. The viscosity enhancing material 1421 enhances the viscosity of the adhesive and thereby creep resistance, but also reinforces the adhesive and thereby increases the adhesive's resistance to shock and shearing forces. In the example illustrated by FIG. 15B, the adhering layer 1413 is composed of an adhesive 1422 and the viscosity enhancing material 1421 is omitted.

The adhesive 1422 can take a wide variety of different forms. In one exemplary embodiment, the adhesive 1422 is preferably a viscoelastic material which converts vibration into heat energy by shear forces developed within the viscoelastic material. Any suitable viscoelastic adhesive material can be used if it remains viscous after curing. For instance, the adhesive can be any one or more of the following adhesives: a pressure sensitive hot or cold melt adhesive, an acrylic based adhesive such as acrylic viscoelastic polymers, pressure sensitive damping polymers, adhesive epoxy resins, urea resins, melamine resins, phenol resins, vinyl acetates, cyanoacrylates, urethanes, synthetic rubbers, etc. The adhesive can be, for example, any one of a variety of commercial adhesives such as the acrylic adhesive A-1115 from Avery-Dennison, the acrylic adhesive MACtac™ XD-3780 from Morgan Adhesives, the synthetic rubber based hot melt adhesive R-821 from The Reynolds Co., or the acrylic adhesive V-514 from Venture Tape.

The viscosity enhancing material 1421 of the adhering layer 1413 generally reduces the fluidity of the resulting adhesive layer, thereby generally reducing the amount of both static and dynamic creep exhibited within the vibration damping system. The viscosity enhancing material 1421 may include one or more of the following exemplary materials: organic fibers including cellulose, carbon fiber, asbestos, and inorganic fibers including glass fiber, steel wool, synthetic fibers, etc.

The viscosity enhancing material 1421 provides a structure interposed between the vibration generating source such as the drum 16 of the dryer and the constraining layer 1412. This structure permits the drum sidewall 28 and the constraining layer 1412 to move relative to one another within confines, but increases the viscosity (i.e., resistance to flow) of the adhering layer 1413 so that permanent shifts between the constraining layer 1412 and the drum sidewall 28 are reduced. In other words, the constraining layer 1412 in general does not creep relative to the drum sidewall 28 as much as in an identical damping system that doesn't include the viscosity enhancing material 1421.

In one exemplary embodiment, the viscosity enhancing material 1421 of the adhering layer 1413 is a cellulose material, the fibers of which are dimensioned and matted to permit penetration of the adhesive in its liquid state into the cellulose carrier material, which may be accomplished by soaking the cellulose material in the adhesive, by pressurized extrusion, by rolling, or by any other suitable method. The penetration can be within microns or throughout the cellulose material.

The adhering layer 1413 is produced by applying an adhesive 1422 in a liquid state to the viscosity enhancing material 1421 and curing the adhesive 1422 to form an adhesive coated core. A number of processes can be used to apply the adhesive 1422 to the viscosity enhancing material 1421 or to carrier materials. For instance, a roll coat process (metered adhesive liquid is applied to one or both of two or more opposing rollers between which a core, e.g., the viscosity enhancing material, passes), spray coating, brush coating, knife coating, foam (stable bubbles) or froth (the bubbles of which dissipate to leave a thin coat) coating in the form of applying mechanically or chemically agitated adhesives, curtain coating, slot die or extruded coating (with the carrier or viscosity enhancing material passing through a slot in which adhesives are injected), or calendaring, for example. Appropriate release films may be formed or placed on the major surfaces (top and/or bottom) of the adhesive coated core or adhering layer 1413 in a known fashion.

In some exemplary embodiments, the adhering layer 1413 of the embodiments illustrated by FIGS. 14A, 14B, 15A, and 15B is replaced with a non-adhesive material. A wide variety of different non-adhesive materials can be used. In one exemplary embodiment, the non-adhesive layer is a viscoelastic material which converts vibration into heat energy by shear forces developed within the viscoelastic material or an elastic material. Any suitable viscoelastic adhesive material can be used. Examples of suitable non-adhesive materials include, but are not limited to, ethylene vinyl acetate (EVA), and blends of EVA, and other polymers, including blends of EVA with one or more of polypropylene, nitrile rubber, and ethylene-styrene interpolymers. Additional examples include, but are not limited to, acrylics, such as acrylic viscoelastic polymers, epoxy, ureas, melamines, phenols, vinyl acetates, cyanoacrylates, urethanes, synthetic rubbers, etc.

Referring to FIGS. 18 and 19, in one exemplary embodiment the dampers 100 are configured to drive acoustic energy from one area of the dryer 10 to another area of the dryer. For example, the dampers 100 can be configured to drive acoustic energy generated at the front of the drum 16 toward the rear of the drum (See Arrow 1800 in FIGS. 18 and 19). This shifting of the acoustic energy can be accomplished in a wide variety of different ways. Damper features that drive acoustic energy from one location to another location are referred to as “acoustic shifting features” 1900 in this application. The following are examples of acoustic shifting features:

-   -   Portions of the damper 100 may be stiffer than other portions of         the damper (for example due to bending—See FIGS. 16 and 17);     -   Portions of the damper may be larger than other portions of the         damper;     -   Portions of the damper may be thicker than other portions of the         damper;

Portions of the damper may be denser or heavier than other portions of the damper and/or;

Portions of the damper may be made from other materials than other portions of the damper.

In the example illustrated by FIG. 18, acoustic shifting features 1900 are provided on a front portion 1902 of the dampers 100 that is positioned close to the access opening 23 of the drum 16. The acoustic shifting features 1900 force the vibration energy toward the back end 1904 of the drum 16. In one exemplary embodiment, the acoustic shifting features 1900 make a front portion 1912 of the drum stiffer than the back end 1914 of the drum 16. The stiffer front portion 1912 of the drum 16 forces the vibration energy toward the less stiff back end 1914 of the drum 16.

In the example illustrated by FIG. 19, acoustic shifting features 1900 are provided on the dampers 100 that are positioned between the access opening 23 and the belt groove 21 of the drum 16. In the example illustrated by FIG. 19, the acoustic shifting features 1900 are patterned to control the shifting of the vibration energy. The acoustic shifting features 1900 can be patterned in a wide variety of different ways. In one exemplary embodiment, the acoustic shifting features are configured to aggressively drive the vibration energy at the front end 1902 of the drum 16 rearward and then less aggressively drive the vibration energy toward the rear of the drum as the distance between the front of the drum and the rear of the drum increases. This can be accomplished in a wide variety of different ways. In the illustrated embodiment, the acoustic shifting features 1900 a and 1900 b that are closer to one another than the acoustic shifting features 1900 b and 1900 c. In one exemplary embodiment, the acoustic shifting features 1900 make the front end 1902 of the drum 16 most stiff and then gradually less stiff toward the rear of the drum as the distance between the front of the drum and the rear of the drum increases. This gradual change in stiffness can be accomplished in a wide variety of different ways. For example, more closely spaced bends closest to the front of the drum and bends spaced farther apart as the distance from the front of the drum increases, the width of the damper tapers as the distance from the front of the drum increases, the thickness of the damper tapers as the distance from the front of the drum increases, the weight of the damper declines as the distance from the front of the drum increases, and portions of the damper that are farther away from the front of the drum are made from less stiff materials.

In the examples illustrated by FIGS. 18 and 19 the acoustic shifting features 1900 are illustrated as extending generally in the direction of the circumference of the drum 16. FIG. 20 illustrates an exemplary embodiment where the acoustic shifting features extend along the length L_(DRUM) of the drum. It should be appreciated from FIGS. 18-20 that the acoustic shifting features can extend in any direction and can have any configuration.

The dampers 100 disclosed by the present application can be used on any vibrating system which requires damping on any surface. For instance, the dampers 100 can be used to dampen vibration of any surface of a cabinet or housing, drum, moving part, etc. of any machine. Examples of applications for the dampers 100 disclosed by the present application include, but are not limited to, clothes washing machines (for example, a tub, basket, motor, or other moving part and/or a cabinet or housing or other stationary part of the clothes washing machine), air conditioners (for example, a compressor, vent, housing, or other part of the compressor and/or a cabinet, housing, heat exchange coil or other stationary part of the air conditioner), components of heating ventilation and air conditioning systems (for example, fans, blowers, ducts, plenums, and the like), refrigerators (for example, fans, compressors, or other moving parts and/or a cabinet, housing, heat exchange coil or other stationary part of the refrigerator), fans, squirrel cages of fans, small appliances (for example, a motor or other moving part and/or a cabinet or housing or other stationary part of the appliance), blenders (for example, a motor or other moving part and/or a housing or other stationary part of the blender), vacuums (for example, a motor, brush, impeller or other moving part and/or a housing or other stationary part of the vacuum), mixers (for example, a motor or other moving part and/or a housing or other stationary part of the mixer), white goods (for example, a motor or other moving part and/or a housing or other stationary part of the white good), industrial equipment (for example, a motor or other moving part and/or a housing or other stationary part of the industrial equipment), generators (for example, a motor or other moving part and/or a housing or other stationary part of the white good), light sets, articles with metal that vibrates, mufflers (for example, the external housing or internal components of the muffler), engines, such as gasoline and diesel engines, engine accessories, such as radiators, pumps, intake manifolds, exhaust manifolds, air conditioners, heaters, heater blowers, and the like, industrial grade food processing equipment (for example, drums, mixers and the like), commercial and residential equipment and devices, panels of automobile doors, trunks, hoods, etc. and aeronautical applications, and electronic devices. The present invention can be applied anywhere vibration or sound damping is appropriate.

The above description of specific embodiments has been given by way of example. From the disclosure given, those skilled in the art will not only understand the general inventive concepts and attendant advantages, but will also find apparent various changes and modifications to the structures and methods disclosed. For example, the general inventive concepts are not typically limited to any particular application or damper configuration. Thus, for example, use of the inventive concepts on all types of devices needing vibration and/or sound deadening, are within the spirit and scope of the general inventive concepts. As another example, although the embodiments disclosed herein have been primarily directed to a dryer, the general inventive concepts could be readily extended to any application which could benefit from the damper configurations disclosed herein. It is sought, therefore, to cover all such changes and modifications as fall within the spirit and scope of the general inventive concepts, as described and claimed herein, and equivalents thereof.

Several exemplary embodiments of vents are disclosed by this application. Vibration dampers and devices with vibration dampers in accordance with the present invention may include any combination or subcombination of the features disclosed by the present application.

While the present invention has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Still further, while specifically shaped features have been shown and described herein, other geometries can be used including elliptical, polygonal (e.g., square, rectangular, triangular, hexagonal, etc.) and other shapes can also be used. Therefore, the invention, in its broader aspects, is not limited to the specific details, the representative apparatus, and illustrative examples shown and described. Accordingly, departures can be made from such details without departing from the spirit or scope of the applicant's general inventive concept. 

1. A clothes dryer comprising: a cabinet; a rotatable drum mounted within the cabinet; a plurality of baffles mounted inside the rotatable drum; a plurality of vibration dampers mounted between the baffles and the rotatable drum.
 2. The clothes dryer of claim 1 wherein the baffles are secured to the drum with fasteners and the vibration dampers are also secured to the drum with said fasteners.
 3. The clothes dryer of claim 1 wherein the vibration dampers are constrained layer vibration dampers.
 4. The clothes dryer of claim 1 wherein the vibration dampers include at least one acoustic shifting feature.
 5. The clothes dryer of claim 4 wherein the acoustic shifting feature is configured to shift acoustic energy generated at the front of the drum toward the rear of the drum.
 6. A clothes dryer comprising: a cabinet; a rotatable drum mounted within the cabinet; a plurality of baffles mounted inside the rotatable drum; a plurality of vibration dampers attached to the rotatable drum such that a largest dimension of the vibration dampers extends in a direction of a length of the rotatable drum.
 7. The clothes dryer of claim 6 wherein the vibration dampers are attached between the baffles and the rotatable drum.
 8. The clothes dryer of claim 6 wherein the vibration dampers are mounted to an outside surface of the rotatable drum.
 9. The clothes dryer of claim 6 wherein the baffles are secured to the drum with fasteners and the vibration dampers are also secured to the drum with said fasteners.
 10. The clothes dryer of claim 6 wherein the vibration dampers are constrained layer vibration dampers.
 11. The clothes dryer of claim 6 wherein the vibration dampers include at least one acoustic shifting feature.
 12. The clothes dryer of claim 11 wherein the acoustic shifting feature is configured to shift acoustic energy generated at the front of the drum toward the rear of the drum.
 13. A clothes dryer comprising: a cabinet; a rotatable drum mounted within the cabinet; a plurality of vibration dampers mounted to the rotatable drum; wherein the vibration dampers include acoustic shifting features configured to shift acoustic energy generated at the front of the drum toward the rear of the drum.
 14. The clothes dryer of claim 13 wherein the vibration dampers are mounted between the baffles and the rotatable drum.
 15. The clothes dryer of claim 13 wherein the vibration dampers are mounted to an outside surface of the rotatable drum.
 16. The clothes dryer of claim 13 wherein the baffles are secured to the drum with fasteners and the vibration dampers are also secured to the drum with said fasteners.
 17. The clothes dryer of claim 13 wherein the vibration dampers are constrained layer vibration dampers.
 18. The clothes dryer of claim 13 wherein the vibration dampers include at least one acoustic shifting feature. 